An electric toothbrush in which the entire driving motor vibrates and these vibrations are transmitted to the brush head, is known from U.S. Pat. No. 3,196,299. The driving motor drives an imbalance in the form of an eccentrically supported mass and forms a vibratory drive together with this imbalance. The driving motor is arranged in a chassis that, in turn, is movably arranged on the housing of the toothbrush by means of a spring. The vibrations of the drive are transmitted to a transmission rod that is movably arranged in the housing and to which a clip-on brush can be attached. The spring is clamped between corresponding shoulders of the chassis and the housing and arranged at a through-opening of the housing between the clip-on brush and the driving motor. In this case, a relatively complicated screw mechanism is provided for changing the spring prestress in order to thusly vary and adapt the intensity of the vibrations or the motion amplitude of the drive to the requirements of different users. Despite this adjustability, one unsatisfactory aspect of such vibratory drives can be seen in that the brush head carries out an excessively intense poking motion while the wiping motion parallel to the tooth flanks is comparatively weak. In addition to a limited efficiency, this can lead to the user experiencing an unpleasant sensation while the toothbrush is used.